You have a distance and a time so you can work out the bikes speed which would be distance/time so 40mph.
True. That is how powerful the sun is. But it will explode in only about 5 billion years.
To develop this problem it is necessary to apply the concepts related to Wavelength, The relationship between speed, voltage and linear density as well as frequency. By definition the speed as a function of the tension and the linear density is given by

Where,
T = Tension
Linear density
Our data are given by
Tension , T = 70 N
Linear density , 
Amplitude , A = 7 cm = 0.07 m
Period , t = 0.35 s
Replacing our values,



Speed can also be expressed as

Re-arrange to find \lambda

Where,
f = Frequency,
Which is also described in function of the Period as,



Therefore replacing to find 


Therefore the wavelength of the waves created in the string is 3.49m
Answer:C
Explanation: I studied, and C is correct
Im pretty sure burning paper
its either that or melting iron but im 90 percent sure its paper burning